Central RR of New Jersey 2-6-2 "Prairie" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class J-1s/SU23 (Locobase 5312)

Data from American Engineer and Railroad Journal (June 1902), supplemented by CNJ 7 - 1944 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 28 April 2019 email correcting the engine weight.)

In 1919, this class was designated J1. As delivered, the 20 purchased by the CNJ in 1902 are shown in Locobase 12655. The last five were originally delivered to the Long Island Railroad and were sold to the CNJ in November 1911.

Later the boiler was superheated to the dimensions shown in the specs. Six had been modified by 1923--203, 206, 213, 217-219. By 1930, only 205, 209-210 remained to be done. The class had 10 1/2" (268 mm) piston valves. By then, coal capacity had increased to 6 tons or, with increased coal flares, 7 tons--quite a bit for a tank locomotive.

Most of the class was scrapped between 1935 and 1940. The 1945 reclassification, which combined letter codes with the tractive effort in thousands, gave the survivors--201, 207, 214-215, 220-224--class SU23. A virtually simultaneous event was the mass retirement and scrapping of these locomotives in July 1945.

Class J1 (Locobase 12655)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 24, p. 253 and Volume 25. p. 210. See also "New Suburban Engines of the Central Railroad of New Jersey", Railroad Gazette, Volume XXXIV [34], No. 25 (20 June 1902), pp. 462-463; and E E R Tratman, "Tank Locomotives", Official Proceedings of the Western Railway Club (Chicago: W F Hall Printing Company, 1905), pp. 349-350. for details on their operation. (Thanks to Chris Hohl for his 13 April 2019 email reporting the class's coal capacity.) Works numbers were 20245 in April 1902; 20839-20840, 20867, 20882-20883 in August; 20906-20908, 20940-20942 in September; 22397, 22401, 22412 in June 1903; 22432, 22444, 22492, 22499, 22518 in July.

Commuter side-tank engine remarkably similar to that described on Locobase 472. "The popular idea of the ordinary 'suburbanite' [passenger], that a railroad always uses engines on HIS trains, which won't make time with expresses," the Railroad Gazette contended in its report,"must give way before the up-to-date machinges which have been put to work on this exacting service on the Central Railroad of New Jersey."

Firebox heating surface included 43 sq ft (4 sq m) of arch tubes. The heating surface area to grate area ratio of 33.4: 1 suggests a Wootten-type firebox and the type did indeed use a wide grate to burn "hard coal". But the design perforce had to use a conventional cab because of the large coal "box" behind it.

The two water tanks were filled through a pipe that dropped straight down through the coal box, entering a Y pipe that sloped down to a central point under the cab. From here the water filled each side tank equally, air being vented from manholes in the top of each. A pocket at the junction of the Y allowed the locomotive's injectors to take water from the lowest point in the system and on the centerline.

"Side swash" (water sloshing from one side to the other) was reduced both by the water being divided between the side tanks and the Y pipe. And coal shifting was held in check by the design of its box and by the Rushton radial truck under it, which was given "ample play and guides the engine steadily round curves." All in all, the "arrangement", said RG, meant "the engine experiences the least possible disturbance in running fast through curves."

These engines hauled suburban trains from Jersey City south to Perth Amboy (21.1 miles/34 km/h) or west to Somerville, NJ (34.7 miles/55.9 km/h). The trains were made up of 2-10 cars each weighing between 55,000 and 62,000 lb (24,948-28,123 kg). The Perth Amboy could take anywhere from 32-52 minutes, the shorter time representing a two-car train making two stops and averaging 39.6 mph (63.75 km/h) and the longer time a 20-stop train averaging 24.3 mph (39.1 km/h). This was, said RG soon after their introduction," [v]ery satisfactory service"as they hauled 10-12 coaches at "good average speed."

The class was superheated in the 1920s; see Locobase 5312. Five engines sold to the Long Island Railroad had very similar dimensions - see Locobase 9078

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID5312 12655
RailroadCentral RR of New JerseyCentral RR of New Jersey
Number in Class2525
Road Numbers200-224200-224
Number Built25
BuilderCNJBurnham, Williams & Co
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)14 / 4.2714 / 4.27
Engine Wheelbase (ft / m)31.67 / 9.6531.67 / 9.65
Ratio of driving wheelbase to overall engine wheelbase 0.44 0.44
Overall Wheelbase (engine & tender) (ft / m)31.67 / 9.6531.67 / 9.65
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)137,500 / 62,369129,200 / 58,604
Engine Weight (lbs / kg)206,400 / 94,529189,900 / 86,137
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)206,400189,900
Tender Water Capacity (gals / ML)3000 / 11.363000 / 11.36
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)6 / 65 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)76 / 3872 / 36
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 160063 / 1600
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)18" x 26" / 457x66018" x 26" / 457x660
Tractive Effort (lbs / kg)22,731 / 10310.6222,731 / 10310.62
Factor of Adhesion (Weight on Drivers/Tractive Effort) 6.05 5.68
Heating Ability
Tubes (number - dia) (in / mm)130 - 2" / 51249 - 2" / 51
Flues (number - dia) (in / mm)20 - 5.375" / 137
Flue/Tube length (ft / m)12.51 / 3.8113 / 3.96
Firebox Area (sq ft / m2)123.80 / 11.51137.40 / 12.76
Grate Area (sq ft / m2)54.50 / 5.0754.50 / 5.06
Evaporative Heating Surface (sq ft / m2)1357 / 126.121832 / 170.20
Superheating Surface (sq ft / m2)266 / 24.72
Combined Heating Surface (sq ft / m2)1623 / 150.841832 / 170.20
Evaporative Heating Surface/Cylinder Volume177.15239.16
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,90010,900
Same as above plus superheater percentage12,64410,900
Same as above but substitute firebox area for grate area28,72227,480
Power L111,9806906
Power MT576.25353.52

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